CN115281694A

CN115281694A - System and method for mobile imaging system

Info

Publication number: CN115281694A
Application number: CN202210396161.1A
Authority: CN
Inventors: G·S·萨姆帕斯·库马尔; A·切蒂; C·贾布罗诺夫斯基; S·P·施罗德; A·曼达尔
Original assignee: GE Precision Healthcare LLC
Current assignee: GE Precision Healthcare LLC
Priority date: 2021-05-03
Filing date: 2022-04-15
Publication date: 2022-11-04
Also published as: EP4085842A1; US20220346735A1; US11510639B2

Abstract

The invention provides a system and method for a mobile imaging system. The present invention provides a method and system for collapsing a column of a mobile imaging system. In one example, a method may include collapsing a column coupled to a mobile imaging system in response to user interaction while concomitantly driving the mobile imaging system.

Description

System and method for mobile imaging system

Technical Field

Embodiments of the subject matter disclosed herein relate to enabling a column to collapse when driving a moving x-ray system.

Background

Mobile imaging systems, such as mobile x-ray devices, are typically mounted on a motorized mobile drive system, such as a cart that can be driven to a patient position. The cart typically has four wheels, including a pair of wheels driven by a motor to move the system. The imaging assembly (such as an x-ray source or tube) may be enclosed in a horizontal tube arm, which may be mounted on a column near the front of the cart.

A mobile imaging system such as a mobile x-ray unit may include an expandable tube arm attached to a column. In addition, at the end of the tube arm opposite the column, an imaging assembly, such as an x-ray tube and collimator, may be attached. The tube arm may comprise several nested sections which may be extended and retracted in a telescopic manner. The column may be rotatable relative to the cart, thereby causing the tube arm to rotate relative to the cart while being fixed relative to the column; in addition, the tube arms can extend and collapse radially and translate linearly up and down the column. The column may further comprise a plurality of nested sections which may extend to a point of maximum extension and may collapse to a lowermost ending position. After operation of the mobile x-ray system, to secure the tube arm used to move the mobile imaging system from one location to another (such as from one patient to another on a hospital floor), the tube arm may be placed in a parked orientation and the column may be placed in a first collapsed orientation. Additionally, the post may further transition from the first collapsed orientation to the end orientation. Parking the tube arm and collapsing the column to the ending position may make the mobile x-ray system more compact and may therefore allow an operator of the mobile x-ray system to easily transport.

To manipulate the imaging assembly and the tube arm, there may be a manually actuatable component such as a first handle attached to the imaging assembly. Using the first handle, the operator can rotate the imaging assembly relative to the tube arm and orient the tube arm for imaging the patient. To transport the mobile imaging system, the cart may have a second manually actuatable component, such as a second drive handle at the rear of the cart for pushing by the operator. Using the second handle, the operator may drive the cart to a position, position the cart proximate to the patient's bed, and position the imaging assembly to image the anatomy of interest.

Disclosure of Invention

In one embodiment, a system comprises: upon satisfaction of the conditions for moving the imaging system, a column coupling the imaging assembly to the drive system is collapsed while concomitantly moving the drive system. In this manner, by driving the imaging assembly while collapsing the assembly to an end orientation, the time between successive scans using a mobile imaging system may be reduced.

It should be appreciated that the brief description above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

Drawings

The invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, in which:

FIG. 1 shows a front view of an exemplary mobile imaging system.

FIG. 2 shows a block diagram of an actuation mechanism of components of the mobile imaging system of FIG. 1.

FIG. 3 shows a schematic diagram illustrating the orientation of a component tube arm of the mobile imaging system of FIG. 1.

Fig. 4A illustrates an exemplary embodiment of a mobile imaging system including a tube arm and column in a first orientation.

Fig. 4B illustrates an exemplary embodiment of the mobile imaging system in a second orientation.

Fig. 4C shows an exemplary embodiment of the mobile imaging system in a third orientation.

Fig. 4D illustrates an exemplary embodiment of the mobile imaging system in a fourth orientation.

Fig. 4E shows an exemplary embodiment of the mobile imaging system in a fifth orientation.

Fig. 5A-5B show a flow chart illustrating an exemplary method for collapsing a column when driving a moving imaging system.

Fig. 6 illustrates a first exemplary timeline for collapsing a column and driving a mobile imaging system according to the present disclosure.

Fig. 7 illustrates a second exemplary timeline for collapsing pillars when driving a mobile imaging system according to the present disclosure.

Detailed Description

The present disclosure relates to a mobile imaging system that allows a column of the mobile imaging system to collapse while allowing an operator to drive the mobile imaging system. An exemplary embodiment of a mobile imaging system is given in fig. 1, specifically showing a column containing two nested sections. Fig. 2 shows a system architecture in the form of a block diagram of the mobile imaging system of fig. 1. Fig. 3 illustrates an exemplary orientation of a tube arm of a cart relative to the mobile imaging system of fig. 1. Fig. 4A-E illustrate exemplary orientations of a mobile imaging system during a transition from a first operating orientation to a fifth, fully collapsed orientation. Specifically, fig. 4A-E show a tube arm comprising two nested sections. 5A-B show a flow chart illustrating an exemplary method for transitioning a mobile imaging system from a first orientation, as shown in FIG. 4A, to a fifth orientation, as shown in FIG. 4E.

As part of operating a mobile imaging system, an operator may align a tube arm and a collimator mounted at the end of the tube arm in a particular orientation relative to a patient in order to scan the anatomy of the patient. As an example, as part of aligning the mobile imaging system relative to the patient, the mobile imaging system may be positioned proximate to the patient's bed. Further, the post may be in a fully extended orientation, the tube arm may be fully extended radially, and the tube arm (in combination with the post) may be axially rotatable. After the operator completes the imaging process, it may be desirable to shift the system to a different position. The mobile imaging system may be reoriented from an operational orientation to a fully collapsed orientation, which may be effective for transport of the cart. The fully collapsed orientation may include the tube arms fully radially retracted, secured to the cart of the mobile imaging system via the latch in the parked orientation, and the column collapsed to a lowermost, end orientation.

As part of moving the imaging system from the imaging orientation to the fully collapsed position for transport, the operator may have to wait for the tube arm to first return to the fully parked position before the column begins to fully collapse. When the tube arm is parked and the column is fully collapsed at the end position, the operator may begin driving the cart. This process can be time consuming in environments where an operator may have many patients to care for within strict time limits (e.g., in an intensive care unit or emergency room environment).

In one example, parking of the tube arm may be initiated by applying a force on a first handle coupled to the imaging assembly. The imaging assembly may be coupled to the column via a rotatable and extendable tube arm, wherein the column couples the tube arm to the drive system. Tube arm parking can be performed by rotating the tube arm to the home orientation, retracting the tube arm toward the column to the fully retracted orientation, and driving the tube arm vertically down the column. Further, retraction of the tube arm may be based on a first input from a first orientation sensor coupled to the column indicating a radial orientation of the tube arm, vertical driving of the tube arm may be based on a second input from a second orientation sensor coupled to the tube arm indicating a vertical orientation of the tube arm relative to the column, and rotation of the tube arm may be based on a third input from a third orientation sensor coupled to the column indicating an angular displacement of the column and the tube arm relative to the origin orientation. Each of the post and tube arm may move linearly downward even after the operator releases the first handle. The operator may initiate movement of the cart by applying a force to the second handle as the tube arm transitions to the parked orientation and the column transitions to the first collapsed orientation. After the tube arm and column are in the parked orientation, the operator may then initiate collapsing the column to the ending orientation via the drive handle switch or by continuing to exert force on the second handle while driving the cart. As an example, movement of the column from the parked orientation to the fully collapsed orientation may be concomitantly performed when driving the cart forward. The speed of movement of the cart may be adjusted based on force feedback from the second handle while the column may collapse at a constant speed.

In this manner, by not waiting for the column to fully collapse before beginning to drive the cart, the mobile imaging system can be transported to a desired location more quickly, thereby saving valuable time in the hospital floor. Even after release, parking actuation of the tube arm in response to initial operator input to the first handle allows the system to more efficiently transition to an orientation in which the tube arm is fixed for travel. In addition, the operator may initiate movement during parking of the tubing arm, allowing for faster transition from imaging to transport. Collapsing the posts while simultaneously driving the cart may provide a time saving mechanism while still minimizing any visual obstruction caused by the posts. In general, by accelerating the parking of the tube arm and collapsing the column to the end position without waiting for the cart to be driven, the user's workflow can be made more efficient.

Fig. 1 shows an example 100 of a mobile imaging system 10 that may be used in the medical or other fields. The mobile imaging system 10 has a drive assembly 12 and an operator console 14 that may be supported by the drive assembly 12. The drive assembly 12 includes a frame 13 (also referred to herein as a cart), two rear drive wheels 18 (one wheel shown) coupled to the frame at a rear end 26 of the mobile imaging system 10, and two front wheels 20 (one wheel shown) coupled to the frame at a front end 28 of the mobile imaging system 10.

The post 33 is attached to and extends upwardly from the frame of the drive assembly 12 and rotates or swivels relative to the drive assembly 12. The post 33 includes an outer section 17 and an inner section 16 nested within the outer section 17. The inner section 16 is fixed to the cart 13, while the outer section 17 can telescope outward from the inner section 16 in response to manipulation by an operator. The outer section may have a range of motion defined by a maximum focus (where the posts 33 are fully extended and the

sections

16 and 17 have a minimum overlap) and a minimum focus (where the posts are fully collapsed at an ending position, where the outer section fully encapsulates the inner section). The tube arm 32 is fixed to the column 33, extending perpendicular to the column. Tube arm 32 may be vertically adjustable relative to post 33 and may otherwise be fixed in its orientation relative to the post. In other words, the tube arm 32 may not rotate independently of the column 33, but may rotate with the column as the column rotates relative to the cart 13. The tube arms may be vertically translated along an axis 120 defined by the length of the post 33 and independently, for example, in response to user manipulation. The tube arm 32 may also telescope (such as extending in and out horizontally) relative to the post 33, allowing components mounted at the outer end of the tube arm 32 to move closer to or further away from the post 33.

An imaging assembly, here in the form of a radiation source 34 including an x-ray source assembly 15, is attached to the outer end of the tube arm 32 and has an x-ray tube housing 22 containing an x-ray source (not shown). The collimator 24 is attached to the tube housing 22 and is rotatable relative to the tube housing 22. The X-ray detector 36 detects X-ray data and may communicate with the imaging controller 27 wirelessly or through a cable 37. Attached to the imaging assembly is a first manually actuatable handle 66 (referred to herein as a first handle) that an operator can use to orient the tube arm and imaging assembly relative to the cart.

Tube arm 32 may include a first force sensor 406. By way of example, the first force sensor 406 may be placed on the topside of the tube arm 32 at the base of the tube arm 32 where the tube arm meets the post 33. The first force sensor 406 may measure forces along three separate, mutually perpendicular axes, such as a radial force applied to the first handle 66 that may act to expand or retract the tube arm 32, a vertical force applied to the tube arm 32 that may act to linearly translate the tube arm 32 up or down relative to the post 33, and a tangential force applied to the first handle 66 that may act to co-rotate the post 33 and the tube arm 32. Additionally, the first force sensor 406 may be coupled to a cord contained within the column 33. The cord may exit the column outer section 17 and be attached to the tube arm proximate the first force sensor 406, and the first force sensor 406 may be further configured to measure a force on the tube arm 32 caused by the cord (as described with respect to fig. 4A-E). The signal generated by the first force sensor 406 in response to the force applied to the first handle 66 may be sent to the controller 50, which may then actuate movement of the tube arm 32 and/or post 33, as described in more detail in fig. 2.

Sensors may be included in the imaging assembly to measure the orientation and/or acceleration of various components. As an example, a first orientation sensor 42 coupled to tube arm 32 may estimate an orientation of tube arm 32 relative to column 33 and cart 13, which may be used to estimate a degree of radial extension or retraction of tube arm 32. During actuation of the tube arm 32, the first orientation sensor 42 may send a signal to the controller 50, which may then actuate additional radial movement of the tube arm 32, as described in more detail with respect to fig. 2. In another example, second position sensor 46 may be coupled to tube arm 32 to estimate a vertical position (along axis 120) of tube arm 32 relative to column 33. The second position sensor 46 may send a signal to the controller 50, which may then actuate vertical translation of the tube arm 32 relative to the post 33, as described in more detail with respect to fig. 2. The sensors 42 and/or 46 may be optical sensors, magnetic sensors, pressure/force sensors, inertial Measurement Units (IMUs), or any variation of these sensors. It may be noted that the sensors of various embodiments may be any one or more suitable types of sensors. For example, one or more sensors may operate based on sensing distance changes using optical, magnetic, electrical, or other mechanisms. In further examples, a third position sensor 48 may be coupled to the column 33 to estimate the angular displacement of the column 33 relative to the cart. The third orientation sensor 48 may send a signal to a controller 50, which may then adjust the rotational movement of the post 33, as described in further detail with respect to fig. 2. The sensor 48 may be an optical sensor, a magnetic sensor, a hall effect sensor, or other suitable sensor adapted to detect the degree of rotation of the column 33. The placement of

sensors

42, 46, and 48 as shown in fig. 1 is exemplary, and other configurations are possible.

The second manually actuatable interface may be provided on the system 10 in the form of a second drive handle 38 (referred to herein as second handle 38) provided on the rear end 26 of the system 10, such as a frame coupled to the drive assembly 12. The controller 50 senses or receives signals based on manipulation (e.g., user manipulation) of the second drive handle 38, and the mobile imaging system 10 may be driven to different positions to image the patient. As an example, the second handle 38 may detect the force applied to the handle via a second force sensor 407 contained within the handle, which may then send a signal to the controller 50 to actuate the drive assembly 12. The drive assembly 12 may include a drive motor 52 and may be configured to drive the rear drive wheel 18.

A patient or subject 29 is typically positioned on a bed or table 30. Once the mobile imaging system 10 is positioned near the table 30, the column 33 is turned or rotated (e.g., via user manipulation) to position the x-ray source assembly 15 directly over the anatomy of the subject 29 to be scanned. The detectors 36 are positioned on opposite sides of the subject 29.

A user interface 44 may be provided proximate the back end 26 of the system 10. Optionally, the user interface 44 may be integral with the second handle 38, or it may be configured as a remote control that may be held in the operator's hand away from the system 10. The user interface 44 may communicate with the controller 50 wirelessly or through a wired connection. The user interface 44 may be one or a combination of buttons, joysticks, toggle switches, power assist handles, configured as keys on a keypad or selections on a touch screen, etc. In some examples, the signal sent by the second handle 38 may be different from the signal sent by the user interface 44. For example, the user interface 44 may send signals to switch drive modes, turn the system 10 on or off, and so forth.

The controller 50 receives information from a plurality of sensors indicating the position of the column 33, tube arm 32, collimator 24, and/or x-ray source assembly 15. In addition, controller 50 may receive force information indicating the degree of force applied to first handle 66 and second handle 38. In response to the orientation information and the force information, controller 50 may actuate a plurality of motors (such as first servomotor 210, second servomotor 212, third servomotor 214, drive motor 52, and column motor 420, all of which will be discussed further with respect to fig. 2) that may control the movement of tube arm 32, column 33, and drive wheel 18 of system 10. Additionally, the controller 50 may receive signals from the user interface 44, as described above.

Fig. 2 shows an example 200 of a control system and components for actuating each of the column, tube arm, and drive assembly of the mobile imaging system 10 of fig. 1. The mobile imaging system 10 may be controlled via a controller 50, which may receive signals from a plurality of sensors as further described herein.

To actuate movement of tube arm 32, controller 50 may receive a signal from first handle 66 via first force sensor 406. As described with respect to fig. 1, the first handle 66 may be coupled to the first force sensor 406. The output of the first force sensor 406 may estimate the force exerted on the first handle. Upon receiving a force signal from the first force sensor 406, the controller 50 may initiate movement of the tube arm via the tube arm actuator 208. Tube arm actuation may include two independent degrees of motion of tube arm 32: radial expansion and retraction of tube arms 32 and vertical translation of the tubes along the column. For each of the independent degrees of motion of tube arm 32, there is a corresponding servomotor, first servomotor 210 and second servomotor 212, to provide force feedback along the respective degree of motion (as further described with respect to fig. 2). Additionally, a third servomotor 214 may be present to provide force feedback for rotation of the column relative to the cart in response to signals received from the first handle 66.

The servo motors may include motors coupled to position sensors, which may then send signals to the motors to actuate in response to the position information. As an example, the servo motors may incorporate internal position encoders, such as rotary encoders, which may estimate the angular position of a shaft contained within the motor. The orientation information of the shaft contained within the motor may then be sent to the controller to actuate the motor. Additionally or alternatively, the servo motor may contain an external orientation sensor that may record the orientation of components external to and driven by the motor. Signals obtained from the external orientation sensor may then be sent to the controller to actuate the motor. Further, the servo motors may be configured to actuate in response to signals from the force sensors in combination with orientation signals received from the orientation sensors.

As an example, the first servomotor 210 may provide power for radial expansion and retraction of the tube arm. This may involve receiving force information from the first force sensor 406 that applies a force radially along the tube arm, in addition to the positional information of the first positional sensor 42 from the outer section of the tube arm 32 (as described with respect to fig. 4A-E). The force information and orientation information obtained from

sensors

406 and 42, respectively, may then be sent to controller 50 to actuate second servomotor 212 to apply a motive force to radially expand or contract tube arm 32 at a set velocity. The set velocity of tube arm 32 may be determined via a force feedback loop based on the estimated radial force from first force sensor 406.

As an example of the force feedback loop described above, a first Proportional Integral (PI) controller may be used to regulate the power delivered to the first servomotor 210. The set point of the first PI controller may be adjusted based on each of the output of the first force sensor 406 and the output of the first orientation sensor 42. The first PI controller may receive a difference between the set-point power and the actual power delivered to the first servo motor 210. At the first PI-controller, the error may be processed and/or modified (scaled) by a proportional gain. The integral of the error may be similarly processed and/or modified (scaled) by an integral gain. Then, one of these terms or the sum thereof is output as a signal. The output signal of the first PI controller may generate a final control signal to be sent to the motor of the first servo motor 210.

As another example, second servomotor 212 may provide the motive force for vertically translating tube arm 32 along column 33. The second servomotor 212 may first receive force information of the force applied vertically along the tube arm from the first force sensor 406, in combination with positional information along the column height from the sensor 46 of the tube arm 32. The force information and orientation information obtained from

sensors

406 and 46, respectively, may then be sent to controller 50 to actuate second servomotor 212 to apply power to translate tube arm 32 up or down at a set speed. The set speed of tube arm 32 may be determined via a force feedback loop based on the estimated vertical force from first force sensor 406.

As an example of the force feedback loop described above, a second Proportional Integral (PI) controller may be used to regulate the power delivered to second servomotor 212. The set point of the second PI controller may be adjusted based on each of the output of the first force sensor 406 and the output of the second orientation sensor 46. The second PI controller may receive a difference between the set point power and the actual power delivered to the second servo motor 212. At the second PI-controller, the error may be processed and/or modified (scaled) by a proportional gain. The integral of the error may be similarly processed and/or modified (scaled) by an integral gain. Then, one of these terms or the sum thereof is output to the signal. The output signal of the second PI controller may generate a final control signal to be sent to the motor of the second servo motor 212.

Similarly, a third servomotor 214 may provide power for axial rotation of the column 33. In addition to the angular orientation information from the third orientation sensor 48, this may involve receiving force information for tangential forces on the tube arm from the first force sensor 406, and then may send the force information and orientation information obtained from

sensors

406 and 48, respectively, to the controller 50 to actuate the third servomotor 214 to apply power to rotate the column 33 at a set speed. The set speed may be determined via a force feedback loop based on the tangential force estimated from the first force sensor 406.

As an example of the feedback loop described above, a third proportional-integral (PI) controller may be used to regulate the power delivered to third servomotor 214. The third PI controller setting may be adjusted based on each of the output of the first force sensor 406 and the output of the third orientation sensor 48. The third PI controller may receive a difference between the set point power and the actual power delivered to the third servomotor 214. At the third PI-controller, the error may be processed and/or modified (scaled) by a proportional gain. The integral of the error may be similarly processed and/or modified (scaled) by an integral gain. Then, one of these terms or the sum thereof is output to the signal. The output signal of the third PI controller may generate a final control signal to be sent to the motor of the third servomotor 214.

Additionally, each of the

servo motors

210, 212, and 214, respectively, may include an internal speed sensor. In alternative embodiments, the orientation sensors (such as the first orientation sensor 42, the second orientation sensor 46, and the third orientation sensor 48) may be replaced with accelerometers.

The controller 50 may also receive input signals from a number of other sources, including the user interface 44, the emergency stop mechanism 101, the emergency column drive stop mechanism 219, and the column switch 218. At any time during operation, the controller 50 may be configured to receive input from and act upon one or more emergency stop mechanisms 101, which may include one or more of buttons, sensors, buffers, etc., and which may act to deactivate the drive wheels 18. The controller 50 may also be configured to receive and act on input from the column drive stop mechanism 219. As an example, the post stop mechanism 219 may deactivate further collapse of the post in response to insufficient power, e.g., from the battery 206. As another example, the controller 50 may interrupt actuation of the column motor 420 in response to the column switch 218. As another example, if the post is in a fully collapsed end state, the post switch 218 may indicate that the post is in a fully collapsed orientation, which may cause the controller 50 to deactivate further collapse of the post 33.

Additionally, the exemplary control system 200 may include a drive assembly 12 that houses the drive motor 52. The drive motor 52 may actuate the drive wheel 18 via the controller 50 in response to a force signal detected by a second force sensor 407 contained within the second handle 38. The drive wheel 18 may rotate at a speed determined via a force feedback mechanism by the force detected by the second force sensor 407. In other words, moving the drive system may include actuating a set of drive wheels 18 coupled to the drive system, wherein the speed of the drive wheels 18 is adjusted based on a signal received from a second force sensor 407 coupled to the second handle 38. The force feedback mechanism for the drive motor 52 may be substantially similar to the force feedback mechanism for the

servo motors

210, 212, and 214, whereby the drive motor 52 may provide power to the drive wheel 18 in response to the force applied to the second handle 38. The power applied to the drive wheel 18 by the drive motor 52 may then cause the drive wheel 18 to rotate at a set speed determined by the force applied to the second handle 38.

The second handle 38 may also include a drive switch 39 that may actuate the collapse of the post from the first collapsed state to the fully collapsed state (as described with respect to fig. 4D-5B).

Further, the exemplary control system 200 may include a column actuator 204, which may include the aforementioned third servomotor 214 and column motor 420. The column motor 420 may be a servo motor that may contain a motor and an internal orientation sensor (such as an encoder or potentiometer) that may record orientation information about an axis within the column motor 420. The extent of extension of the column 33 may be inferred from the position information of the internal position sensor of the column motor 420, wherein the end of travel position is defined by a predefined value within the extension range. Additionally, the column motor may receive force information from the first force sensor 406 and may provide motive force for collapse of the column 33 based on the force information from the first force sensor 406 and orientation information of the degree of extension inferred from the internal orientation sensor of the column motor 420. Additionally or alternatively, the column motor 420 may provide motive force for collapsing the column based on input from the drive switch 39. As a first example, in response to a force applied to the second handle 38, the column motor 420 may drive the column 33 downward at a set speed determined by the force applied to the second handle 38 via a force feedback mechanism. As a second example, the column motor may drive the column 33 downward at a fixed speed in response to input from the drive switch 39.

In addition to the controller 50, the actuators of the system 10, such as the column actuator 204, the drive assembly 12, and the tube arm actuator 208, may be powered by a battery 206, which may be a rechargeable energy storage device.

Fig. 3 is a schematic diagram 300 illustrating the orientation of drive assembly 12 and tube arm 32 relative to one another. Post 33 (not shown in fig. 3) pivots relative to drive assembly 12 at pivot point 108. For example, referring to fig. 1, the center of the post 33 may define the pivot point 108. Drive assembly 12 may have a coordinate system that includes a longitudinal axis 118 extending parallel to the length of drive assembly 12 and symmetrically centered along the length of drive assembly 12, a transverse axis 122 extending perpendicular to longitudinal axis 118 and intersecting longitudinal axis 118 at pivot point 108, and a vertical axis 120 defined by the length of the post (not shown). The vertical axis 120 extends perpendicular to both the longitudinal axis 118 and the lateral axis 122, and intersects both at the pivot point 108.

As shown in fig. 3, post 33 pivots relative to longitudinal axis 118 such that centerline 116 of tube arm 32 is located at a rotational angle Φ relative to longitudinal axis 118. As used herein, the angle of rotation Φ when the centerline 116 of the tube arm coincides with the longitudinal axis 118 is equal to zero and can describe the angle of rotation Φ of the post 33 relative to the longitudinal axis 118. Since the tube arm 32 rotates in unison with the rotation of the post 33, and may not rotate independently of the post 33, the angle of rotation Φ may also refer to the angle of rotation of the tube arm 32 relative to the longitudinal axis. The rotation angle Φ may increase (with a positive value) as the column is rotated clockwise and may increase with a negative value as the column is rotated counterclockwise. When tube arm 32 is in the parked orientation, the angle of rotation Φ is 0 such that tube arm 32 is parallel to longitudinal axis 118. In addition, the tube arm 32 can expand and retract along an axis defined by a centerline as indicated at 110.

Fig. 4A-E illustrate various configurations of the mobile imaging system 10 transitioning from a first orientation to a final orientation of an imaging orientation during transport of the imaging system. Fig. 4A-E also show arrows indicating motion during transitions between orientations of various portions of the mobile imaging system 10, and a coordinate system 480 indicating mutually perpendicular directions x, y, and z.

Fig. 4A shows the mobile imaging system 10 in a first orientation. The first orientation may be an orientation in which the mobile imaging system 10 may be in an imaging configuration for imaging a patient (not shown). As an example, the first orientation may include the post 33 fully extending to a maximum length, the tube arm 32 radially extending to a maximum length, and the post 33 and tube arm 32 being rotated 180 degrees relative to the longitudinal axis. As an example, the extension of the column 33, the extension of the tube arm 32 and the non-zero rotation angle Φ of the column 33 and the tube arm 32 for the imaging configuration may take a series of values.

The internal components of tube arm 32 and post 33 are shown in fig. 4A. Tube arm 32 is shown as containing an inner section 402 nested within an outer section 404, and may extend and retract within a predefined range of motion along an axis of the tube arm (such as the axis defined by centerline 116 of tube arm 32, as shown in fig. 3). Also shown within tube arm 32 is tube arm actuator 208, which may include

servo motors

210 and 212 for two independent degrees of motion of the tube arm, as described in detail in FIG. 2. However, the exact placement of the tube arm actuator 208 and the servo motors contained therein is exemplary. Contained within the post 33 are various components that can actuate the collapse of the post 33 to an end orientation. Housed within both the inner section 16 of the column 33 and the outer section 17 of the column 33 is a first gas spring 412 that can provide a counterbalancing force to the tube arms and column, the additional external load of the cart 13, and the friction between the inner section 16 and the outer section 17, helping to position the column 33 at a particular height. The first gas spring 412 may extend along the entire length of the interior of the column 33. Adjacent the first gas spring 412 is a ball screw 410 which is housed within both the inner section 16 and the outer section 17 and is secured to the top of the interior of the outer section 17. The ball screw 410 may be actuated by a ball nut 416 that is received within the inner section 16 and may be driven by a column motor 420 via a belt drive 414. The column motor is housed within the inner section 16, while the belt drive is placed externally on top of the inner section 16. The ball nut 416 may rotate in response to actuation of the post motor 420 via the belt drive 414, and the outer section 17 may be lowered by downward movement of the ball screw 410 due to rotation of the ball nut 416.

Also inside the post 33 is a tension gas spring 418 (referred to herein as a second gas spring) that is housed within the inner section 16 and is secured internally to the top of the inner section 16. The second gas spring 418 may expand and contract within the inner section 16 and may transmit an upward force to the tube arm 32 via the cord 408. The cord 408 is attached to the top of the interior of the inner section 16 and is under tension and in contact with the second gas spring 418 via a pulley attached to the second gas spring. The cord 408 exits from the top of the inner section 16 and wraps around another pulley within the interior of the outer section 17, exiting the outer section and attaching outside of the tube arm 32. The cord 408 has a fixed length and may be placed under increased tension due to the increased expansion of the second gas spring 418. In the first orientation of fig. 4A, the second gas spring 418 is compressed and the cord 408 extends within the interior of the extended outer section 17.

FIG. 4B illustrates the mobile imaging system 10 transitioning from a first orientation to a second orientation. The second position may include the tube arm 32 rotated from the imaging orientation (an example rotation angle Φ of the post 33 and tube arm 32 is given as 180 degrees in fig. 4A) to an origin position where the rotation angle Φ of the post 33 and tube arm 32 is 0 degrees. The second orientation may also include the tube arm 32 in a fully retracted orientation. The rotation of the tube arm may be due to a force applied to the first handle 66 by the operator 401. In response to the force applied to the first handle 66 by the operator 401, a third servomotor (such as the third servomotor 214 of fig. 1-2) can act to drive the tube arm to rotate at a set speed determined by the applied force via a force feedback mechanism. Additionally, FIG. 4B illustrates retraction of the tubing arms from a fully extended orientation (as shown in FIG. 4A) to a fully retracted orientation. The tube arm retraction may be due to a force applied to the first handle 66 by the operator 401, and in response to the force applied to the first handle 66 by the operator 401, a first servomotor (such as the first servomotor 210 of fig. 1-2) may act to drive the tube arm retraction at a set speed determined by the applied force via a force feedback mechanism. The retraction motion of tube arm 32 is indicated by arrow 450 which is parallel to the x-axis of coordinate system 480.

FIG. 4C illustrates the mobile imaging system 10 transitioning from the second orientation to a third orientation. The third orientation may include the tube arm 32 fully retracted and in the parked orientation. The parked orientation may include tube arm 32 fully radially retracted, tube arm aligned parallel to longitudinal axis 118, tube arm 32 rotated angle Φ of 0 °, and tube arm 32 in a vertically lowered orientation relative to column 33, secured to cart 13 via

latches

53 and 65. Additionally, as part of the parked orientation, the post 33 may be in the first collapsed orientation. The tube arm may translate vertically from a maximum focus (as shown in fig. 4B) to a parked orientation due to the force applied to the first handle 66 by the operator 401; this motion is indicated by arrow 451 parallel to the z-axis of coordinate system 480. The vertical translation of tube arm 32 may be based on force feedback in response to being applied to first handle 66 by operator 401 via a second servo motor (such as second servo motor 212 of fig. 2). The speed at which the tubing arm is parked can be set via force feedback based on the force applied to the handle 66 by the operator 401. Additionally, after the operator 401 applies an initial downward force to the first handle 66, the operator 401 may release the first handle 66 and the tube arm may continue to translate vertically along the axis 120 at a fixed speed determined by the speed of the tube arm when the handle is released and the force applied to the handle when released. When tube arm 32 is lowered to the parked orientation, tube arm 32 may be attached to cart 13 via

latches

53 and 65, which are attached to tube arm 32 and cart 13, respectively.

Latches

53 and 65 may indicate to controller 50, via latch sensor 57, that the tube arm is in the parked orientation when secured. With the tube arms parked, the outer section 17 of the post 33 may be partially retracted from a maximum focus to a first collapsed orientation in response to a force applied to the first handle 66 by the operator 401. The force applied to the first handle 66 is estimated by a first force sensor 406 that detects the direction and magnitude of the force and actuates a post motor 420 via the controller 50 to retract the post. The retraction movement of the outer section 17 is indicated by an arrow 452 parallel to the z-axis of the coordinate system 480. The post motor 420 drives the ball nut 416 via the belt drive 414, which causes downward movement of the ball screw 410, thereby lowering the outer section 17. As an example, the post first collapsed orientation may be 50% between the fully extended orientation and the fully collapsed orientation.

Fig. 4D illustrates the mobile imaging system 10 transitioning from the third orientation to the fourth orientation. The fourth orientation may include the tube arm 32 in the parked orientation and the post 33 in an intermediate orientation between the first collapsed orientation and the end orientation. The intermediate orientation of the column may take a range of values. The outer section 17 of the post 33 may continue to retract in response to a signal received from the operator applied to the drive handle 38, as indicated by arrow 453. Alternatively, the operator may actuate a drive switch 39 located on the instrument panel or near the second drive handle to initiate collapse of the post to the end orientation. Pressing of the second handle 38 by the operator 401 may cause actuation of the post motor 420 via the controller 50, which may drive the outer section 17 downward to a fully collapsed end orientation. During collapse of the post 33 to the ending orientation, the second gas spring 418 may expand to provide additional tension on the cord 408. The time for the column 33 to collapse from the parked state to the end state may be a fixed duration. As an example, the time for the outer section 17 to go from the first collapsed orientation to the end orientation may take less than 2 seconds.

During collapse of the post to the ending position, the operator 401 may apply a force to the second handle 38. The force applied to the second handle 38 may be estimated by a second force sensor 407 contained within the handle. The force sensor 407 may then send a signal to the controller 50, which may then actuate the drive motor 52, thereby actuating the drive wheel 18. The drive wheel may operate simultaneously with the collapsing of the column. The speed of the drive wheel 18 may be determined via force feedback based on the force applied to the second handle 38. The movement of the cart 13 is indicated by arrow 454 which is parallel to the x-axis of the coordinate system 480.

Fig. 4E shows the mobile imaging system 10 in a fifth orientation. In the fifth orientation, the tube arm is parked and the column is in the end orientation with the second gas spring 418 fully expanded to maintain tension in the line 408. The drive wheel 18 may continue to be driven at a speed determined via force feedback from the second handle 38, as described above. The movement of the cart 13 is indicated by the arrow 455 parallel to the x-axis of the coordinate system 480.

In this manner, the system in fig. 1-4E provides a system for a mobile imaging system that includes a controller that stores instructions executable by the controller in a non-transitory memory to: during a first condition, collapsing a column coupling a tube arm of the moving imaging system and the drive system at a first speed while driving the drive system forward at a second speed; and during a second condition, collapsing the column at the first speed while driving the drive system forward at a third speed, the third speed being higher than the second speed.

Fig. 5A-B show a flow chart illustrating a method 500 for parking a tube arm (such as tube arm 32 of fig. 1) and collapsing a column (such as column 33 of fig. 1) to an end position in a mobile imaging device, such as system 10. The instructions for performing the method 500 and the remaining methods included herein may be performed by a controller (e.g., the controller 50 shown in fig. 1-4E) based on instructions stored on a memory of the controller in conjunction with signals received from sensors of the mobile imaging system, such as the sensors described above with respect to fig. 1-4E. The controller may employ an actuator of the mobile imaging system to move the mobile imaging system according to the method described below. Specifically, the controller may employ a drive motor (such as drive motor 52 of fig. 2) to actuate a drive wheel (such as drive wheel 18 of fig. 1), two separate servo motors (such as first servo motor 210 and second servo motor 212 of fig. 2) to actuate tube arm motion along two independent degrees of motion, and a third servo motor (such as third servo motor 214 of fig. 2) and a column motor (such as column motor 420 of fig. 2) to actuate rotation and collapse of a column, respectively.

At 502, the method 500 determines whether a condition for parking the tube arm has been met. The parked condition may include receiving a signal of a force applied by an operator to a first handle (such as first handle 66 of fig. 1). As described with respect to fig. 1, the first handle may translate user movement into movement of the arm and/or column of the mobile imaging system and may be coupled to various sensors, including a first force sensor (such as the first force sensor 406 of fig. 1) that may detect a force applied to the first handle and send a signal to the controller to actuate the tube arm and/or column. The first force sensor may also detect a force on the tube arm due to a cord inside the post (such as cord 408 of fig. 4A-E), and may sense an additional force on the tube arm due to the cord. In addition, the first handle may be coupled to position sensors (such as first, second, and

third position sensors

42, 46, 48 of fig. 1) that may send position signals corresponding to the position of the tube arm relative to a vertical axis (such as axis 120 of fig. 1), the radial extension of the tube arm, and the angle of rotation Φ of the column and tube arm relative to the cart. The conditions for parking the tube arm may also include an indication that the scan is completed by the user via an input to the dashboard. The conditions for parking may also include the drive wheel being deactivated or remaining deactivated, the x-ray source (such as x-ray source 15 of fig. 1) being deactivated or remaining deactivated, the imaging controller (such as imaging controller 27 of fig. 1) being deactivated or remaining deactivated, and the imaging assembly (such as the imaging assembly of fig. 1) being oriented in a starting orientation in which the angle of rotation of the imaging assembly relative to the tube arm is zero.

If the conditions of 502 are not met, the method 500 may proceed to 501 where the tube arm may be maintained under normal operation. Normal operation of the tube arm may include movement of the tube arm and column based on forces exerted on the tube arm, such as rotation, extension, and/or retraction of the tube arm when driven via force feedback by motors (such as the first, second, and third servo motors and the column motor). Method 500 may then proceed to 502 again. If the conditions for the tube arm parking are met, the method 500 may proceed to 504.

At 504, the method 500 may proceed to drive the tube arm to the park orientation based on the force feedback from the first handle. The tube arm may be driven to a parked orientation in response to a force applied to the first handle. The drive motion may involve three separate drive mechanisms, such as rotation of the column (resulting in a corresponding rotation of the tube arm), retraction of the tube arm, and vertical downward translation of the tube arm. In other words, each of the rotation of the tube arm, the retraction of the tube arm, and the vertical drive of the tube arm may be adjusted based on force feedback in response to a first signal received from a first force sensor coupled to a first handle of the tube arm. As an example, actuating the tube arm to the parked orientation may include rotating the tube arm to the origin orientation via rotation of the post (as discussed with respect to fig. 4B), retracting the tube arm horizontally to the fully retracted orientation by retracting an inner tube section within an outer tube section, and translating the tube arm vertically downward along the post. However, the order in which the operations occur is exemplary and may be rearranged. For example, the tube arm may first retract, then the column may be rotated, and finally the tube arm may be placed in the parked orientation. As another example, rotation of the column and retraction of the tube arm may be combined before being in the home position, after which the tube arm may be driven to the parked position.

Driving the tube arm to the parked orientation may include, at 506, rotating the post based on the force feedback in response to the force applied to the first handle. A tangential force applied to the first handle may cause the column and tube to co-rotate with respect to the cart. The angular displacement of the column may be estimated by a third orientation sensor, which may then send a signal to the controller to actuate a third servomotor to drive the rotation of the column at a set speed. The set speed may be set via the force feedback mechanism described with respect to fig. 2 in accordance with the tangential force and angular displacement applied to the first handle. The force feedback mechanism may include determining power to apply to the third servomotor based on the position information and the tangential force information from the third position sensor and the first handle, respectively. The difference between the set point power and the actual power applied to the third servomotor may then be proportional to the tangential force applied to the first handle, as determined by the first PI controller of the first servomotor.

Driving the tube arm to the parked orientation may involve retracting the tube arm based on force feedback at 508 in response to a radial force applied to the first handle. The radially inward force may cause the tubing arms to retract toward the post. For example, the position of an inner section of a telescoping tube arm (such as inner section 402 of fig. 4A-E) may be estimated by a first position sensor, which may then send a signal to a controller to actuate a first servo motor to drive retraction of the tube arm at a fixed speed in response to the radial force applied to the first handle and the position of the inner section of the tube arm via force feedback described with respect to fig. 2. The force feedback mechanism may include determining power to apply to the first servo motor based on position information and radial force information from the first position sensor and the first handle, respectively. The difference between the set point power and the actual power applied to the first servomotor may then be proportional to the radial force applied to the first handle, as determined by the second PI controller of the second servomotor.

Further, driving the tube arm to the parked orientation may also involve linearly driving the tube arm downward based on force feedback in response to a vertical downward force applied to the first handle, at 510. The vertical downward force may cause the tube arm to translate vertically downward along a vertical axis of the column. The position of the tube arm along the vertical axis relative to the column may be estimated by a second position sensor, which may then send a signal to the controller to actuate a second servo motor to drive the tube arm linearly downward at a fixed speed determined by the vertical force applied to the first handle via the force feedback mechanism described with respect to fig. 2. The force feedback mechanism may include determining power to apply to the second servo motor based on position information and radial force information from the second position sensor and the first handle, respectively. The difference between the set point power and the actual power applied to the second servomotor may then be proportional to the vertical force applied to the first handle, as determined by the second PI controller of the second servomotor. Furthermore, the tube arm may be actuated even after the force applied to the first handle ceases, for example, as a result of an operator (e.g., operator 401 of fig. 4B-E) releasing the first handle. After releasing the first handle, the actuation may be determined by the orientation of the tube arm relative to the post, the vertical downward force applied to the handle when released, and the vertical downward velocity of the tube arm relative to the post when released.

While driving the tube arm linearly downward to the parked orientation as indicated at 510, by actuating a ball screw (such as ball screw 410 of fig. 4A-E) by a post motor, the post may be driven downward at a constant speed to a first collapsed orientation, which may not be a fully collapsed end orientation, as indicated at 512. In other words, upon actuation of the tube arm to the parked orientation, the column may be collapsed simultaneously by collapsing the outer column section enclosing the inner column section until the first collapsed orientation is reached. The post motor may be actuated in response to a linear downward force applied to the first handle, which may cause a signal from the first force sensor to be sent to the controller, which may then actuate the post motor to drive an outer section of the post (such as outer section 17 of the post of fig. 1) downward. The post motor may drive the ball screw via a belt drive (such as belt drive 414 of fig. 4A-E), which may then cause the ball nut (such as ball nut 416 of fig. 4A-E) to rotate, forcing the ball screw to rotate in conjunction with the rotational motion of the ball nut and translate linearly downward. Due to the linear downward movement of the ball screw, which may rotate relative to the column (e.g., may be fixed to the top of the interior of the outer section of the column by a flange bearing), may then drive the outer section of the column linearly downward.

At 514, in conjunction with the column drive, weight compensation may be provided inside the column via a first gas spring (such as first gas spring 412 of fig. 4A-E) as the column is driven downward. The first gas spring may provide a counterbalancing force to the column to control the motion of the column as it is driven downward by the column motor. The first gas spring may be secured to the bottom of the inside of an inner section of the column (such as inner section 16 of fig. 1) and the top of the inside of an outer section of the column, and may extend if a compressive force is applied that is less than the extension force of the first gas spring, and may otherwise compress according to the difference in the compressive and extension forces. The compressive force applied to the first gas spring may include the weight of the tube arm, the force of the outer section of the frame and column when not actuated, additional force of the outer section of the frame and column when actuated, and additional frictional forces within the first gas spring. As an example, the force that the first gas spring may apply to the frame and the outer section of the post may be approximately (e.g., with a 5% margin of error) 1300N of full compression force and 800N of full expansion force.

At 516, the method 500 may check whether the tube arm is in a parked state. The tube arm being in the parked state may include the tube arm being securely fastened to the cart via a latch (such as latch 65 fixed to the tube arm and latch 53 fixed to the frame, as shown in fig. 1), the tube arm being fully radially retracted, the column and tube arm having a rotation angle Φ of 0 relative to a longitudinal axis of the cart (such as longitudinal axis 118 of fig. 3), and the column being in the first collapsed orientation. As an example, the latch may include a sensor (such as latch sensor 57 of fig. 1) that may send a signal to the controller to indicate that the tube arm is in the parked orientation when the latch is secured. Additionally or alternatively, the parking position may be indicated by positional data of the tube arm and column estimated by the first, second and third position sensors, which positional data may be stored and recorded in the controller.

If the above conditions for the tube arm parking are not met, it can be concluded that the tube arm parking is not complete. Method 500 may proceed to 503 to determine whether a signal is received from the second handle during parking of the tubing arm. The mobile imaging system may include a second handle (e.g., drive handle 38) that outputs a signal to the controller indicating a desired direction of movement of the mobile imaging system. In one example, the mobile imaging system may also include a switch (such as on a dashboard or on a smart device communicatively connected to the imaging system) that can be actuated to indicate a desire to move the imaging system to an end orientation and to move the system from one location to another. In response to the above-mentioned signals, the controller may activate a drive wheel (such as drive wheel 18 of fig. 1) in order to move the mobile imaging system. Thus, if a signal is received from the second handle, method 500 proceeds to 505 to activate the drive wheel. In one example, the drive wheel may be actuated at a first constant speed. In another example, upon receiving a signal from the second handle, the speed of the drive wheel is adjusted based on the force exerted on the second handle (as estimated by a second force sensor included within the second handle). While driving the drive wheels at the first speed, the method 500 may then proceed to 507, where the pipe arm may continue to be driven to the parked orientation. If no signal is received from the second handle, the method 500 may proceed directly to 507 to drive the tube arm to the park orientation.

If the tube arm is in the parked orientation, the method 500 may then proceed to 518, as shown in FIG. 5B. At 518, the method 500 may determine whether a signal is received from the second handle after the tubing arm is parked. The signal received from the second handle may include a force applied by the operator onto the second handle to manually drive the cart, which may be estimated by a second force sensor (such as second force sensor 407 of fig. 1-4) coupled to the second handle. Also, the signal to move the mobile imaging system may come from a switch (such as on a dashboard or on a smart device communicatively connected to the imaging system) indicating a desire to move the imaging system to an end position and to move the system from one location to another. If no signal is received from the second handle or switch, the method 500 may proceed to 509 and maintain the drive wheel in a deactivated state. The imaging system may not be moved to a different location. In one example, the posts may be actuated to a fully collapsed orientation via the steps described in step 524 of the method, even if the imaging system is not moved to a different position. After 509, method 500 may return.

If a signal is received from the second handle or switch, method 500 may proceed to 520 to initiate actuation of the drive wheel. The received signal may be from a force applied on the second handle and may be estimated by a second force sensor contained within the second handle, which may then send a signal to the controller to drive a drive motor, which may actuate the drive wheel.

The movement of the drive wheel may include adjusting a speed of the drive wheel based on the force feedback at 522. The wheel may be driven by the drive motor in response to a force applied to the second handle based on the force feedback. The force applied to the second handle may be sensed by a second force sensor contained within the handle, which may then send a signal to a controller, which may then drive the wheel at a set speed via a force feedback loop based on the force applied to the second handle. In other words, the speed of the drive wheel is adjusted based on the force exerted on the second manually actuatable component estimated via the force sensor, which is proportional to the exerted force. The control mechanism in the force feedback loop that determines the power applied to the drive motor may be a PI control, as described with respect to fig. 2. The set point of the controller of the drive motor may be adjusted based on an output of a second force sensor included in the second handle and an orientation of the drive wheel inferred based on an output of the orientation sensor. As an example, the orientation sensor may be a sensor inside the drive motor that may continuously measure the angular orientation of the shaft of the drive motor. The controller of the drive motor may receive a difference between the set point power and the actual power delivered to the drive motor. At the PI controller, the error may be processed and/or modified (scaled) by a proportional gain. The integral of the error may be similarly processed and/or modified (scaled) by an integral gain. Then, one of these terms or the sum thereof is output to the signal. The output signal of the controller may generate a final control signal to be sent to the drive motor, which may then actuate the drive wheel at a speed determined by the force applied to the second handle. In one example, the set speed for moving the drive wheel may be proportional to the force applied to the second handle. In another example, the set (second) speed for moving the drive wheel after parking the pipe arm may be higher than the first speed of the actuation wheel when parking the pipe arm.

After initiating movement of the drive wheel in response to the force applied to the second handle, the method 500 may proceed to 524, where the column is driven to a fully collapsed end orientation while the cart is in motion. In other words, actuating the post to the fully collapsed orientation may include collapsing the post from the first collapsed orientation to the end orientation while moving the drive system via actuation of the drive wheel. In one example, the post may collapse at a constant speed regardless of the force exerted on the second handle. In another example, the collapse speed of the column may be based on another force feedback responsive to a second signal received from a second force sensor coupled to the second handle, the collapse speed being proportional to the force exerted on the second handle. Alternatively, the column may collapse even if the movement of the cart ceases, for example if the operator stops applying force to the cart via the second handle.

Driving the post to the fully collapsed end orientation may include collapsing the post to a fully collapsed end state with a post motor and ball screw at 526. Collapsing may include actuating the column motor via a force signal received by a second force sensor contained within the second handle. Additionally or alternatively, column collapse to the end orientation may be initiated by a drive switch on the second handle (such as drive switch 39 in fig. 1). The signal received from the drive handle switch may actuate the column motor via the controller. The post motor may then drive the ball nut via a belt drive, which in turn may drive the ball screw linearly downward as the ball screw is forced to rotate in conjunction with the rotational motion of the ball nut. In response to the linear downward movement of the ball screw, which may rotate relative to the column (e.g., may be attached to the top of the interior of the outer section of the column by a flange bearing), may then drive the outer section of the column linearly downward.

During collapse of the column, as indicated at 528, the first gas spring may provide weight compensation for the column as it collapses to a fully collapsed end orientation. When the post collapses to a fully collapsed end orientation, the first gas spring may be further compressed from a compressed state retained under the post in the first collapsed orientation to another compressed state retained under the post in the fully collapsed end orientation. As an example, when the post collapses to a fully collapsed end orientation, the first gas spring may remain in a maximum compressed state, which may correspond to a compression force of substantially (e.g., with a 5% change) 1300N, as described with respect to 514, or may reach some intermediate compressed state between a fully extended state and a fully compressed state.

Further, during column collapse, at 530, method 500 may proceed to expand the second gas spring. As explained with respect to fig. 4A, the second gas spring is fixed at one end to the top of the interior section of the column and may expand downward toward the base of the interior of the column. At the other end of the second gas spring is a pulley around which a rope can be looped. The cord may be fixed on top of the interior of the inner section of the column, may wrap around a pulley attached to the second gas spring, exits the inner section of the column and extends upwardly into the interior of the outer section of the column. Within the interior of the outer section of the column, the wire rope may loop around another pulley located near the top of the interior of the outer section of the column, may eventually exit the column and attach to the base of the tube arm, and may be coupled to the first force sensor at the base of the tube arm. When the column collapses from the parked state to the fully collapsed end state, the cord may become slack as the relative distance between the attachment point of the cord to the tube arm and the exit point of the cord from the outer section of the column decreases. The second gas spring, which may apply tension to the line rope via the pulley, may counteract the tendency of the line to slacken by expanding in response to a decreasing force applied to the pulley (as the line slackens as the column collapses from the parked condition to the finished condition).

At 532, method 500 may proceed to determine whether the column is in a fully collapsed end position. This may involve a signal from an orientation sensor internal to the column motor to the controller indicating that the column has reached an end range of motion in the fully collapsed state, which may then cause the controller to switch an internal column switch (such as column switch 218 of fig. 2) to an orientation indicating that the column is in the fully collapsed state. The post switch 218 may indicate to the controller that the post is in a fully collapsed state and prevent further actuation of the post motor. If the column switch is not switched to a state indicating that the column is in a fully collapsed state, method 500 may proceed to 511 where method 500 may continue to drive the column to the fully collapsed orientation. In one example, even if the force exerted on the second handle is removed (such as if the operator removes his hand from the second handle), collapse of the post may continue until a fully collapsed state is reached. If it is determined that the column is in the fully collapsed orientation, method 500 may proceed to 534.

At 534, the method 500 can interrupt the drive column while maintaining the cart's motion. As an example, the cart may be in motion as a result of the drive wheel being actuated in response to a force applied to the second handle. In this example, the cart may continue to maintain motion in response to a force applied to the second handle while the post motor is deactivated in response to the controller receiving a signal from the internal post switch indicating that the post has reached the fully collapsed end orientation. As an alternative example, the cart may be in a stationary state, which may cause the drive wheel not to be driven by the drive motor, for example due to no force being applied to the second handle. After 534, method 500 may return.

Fig. 6 illustrates an exemplary timeline 600 for transitioning a mobile imaging system from an imaging configuration (such as during imaging of a patient at a first location) to moving the imaging system to a different second location. The transition includes parking a tube arm (such as tube arm 32, shown in fig. 4A-E), and collapsing a column (such as column 33, shown in fig. 1-2 and 4A-E) to a fully collapsed orientation, and then actuating a drive wheel (such as drive wheel 19, shown in fig. 1-2 and 4A-E) of a drive assembly by a drive motor (such as drive motor 52, shown in fig. 1-2 and 4A-E) to move the mobile imaging system from a first position to a second position. Horizontal (x-axis) represents time, vertical marking t ₁ –t ₆ Representing the significant time of parking, column collapse and drive wheel actuation. In this example, the rotation angle Φ is 0.

The timeline 600 includes a radially-extending graph 602 of a tube arm (such as the inner section 402 of the tube arm 32 shown in fig. 4A-E), where a fully-extended orientation is represented by a "+" on the y-axis and a fully-retracted orientation is represented by a "-" on the y-axis. The vertical orientation of the tube arm is indicated by graph 604, where the maximum focus of the tube arm is indicated by a "+" on the y-axis, the park orientation is indicated by a "0" on the y-axis, and the minimum focus is indicated by a "-" on the y-axis. Dashed line 606 indicates the parking position of the tube arm and is aligned with a "0" on the y-axis of graph 604. Graph 608 indicates the vertical orientation of the column, with the maximum focus indicated by a "+" on the y-axis, the first collapsed orientation indicated by a "1" on the y-axis, and the fully collapsed orientation indicated by a "0" on the y-axis. In addition, dashed line 610 indicates a first collapsed orientation of the post corresponding to a parked orientation of the tube arm and aligned with a "1" along the y-axis of graph 608, and dashed line 612 indicates a fully collapsed orientation of the post and aligned with a "1" along the y-axis of graph 608. Graph 614 indicates a magnitude of a force applied to a first handle (such as first handle 66 of fig. 1-2 and 4A-E) coupled to the imaging assembly, where zero force is indicated by a "0" along the y-axis, and graph 616 indicates a magnitude of a force applied to a second handle (such as second handle 38 of fig. 1-2 and 4A-E) coupled to the drive assembly, where zero force is indicated by a "0" along the y-axis. Graph 618 indicates the speed of the driven wheel, with the stationary wheel indicated as "0" along the y-axis.

At time t ₁ Previously, the tube arm was in an imaging configuration, where the tube arm was fully radially extended, the post was fully vertically extended to the maximum focus, and the rotation angle Φ was 0. At time t ₁ Radial retraction of the tube arm is initiated in response to a force applied to the first handle to transition the tube arm to the parked orientation. At time t ₁ And t ₂ The tube arms are radially retracted from a fully extended orientation to a fully retracted orientation. In response to the force applied to the first handle, the retraction speed of the tube arm from the fully extended orientation to the fully retracted orientation is adjusted based on force feedback from a first servomotor (such as first servomotor 210, shown in fig. 1-2 and 4A-E). At time t ₂ The tubing arms retract to a fully retracted orientation.

At time t ₂ The parking of the tube arm continues in response to the continued force applied to the first handle as shown in graph 614. At time t ₂ And t ₃ In between, each of the tube arm and the column are lowered to the parked orientation and the first collapsed orientation, as indicated by

graphs

604 and 608, respectively. The lowering of the column and tube arm is adjusted via force feedback in response to a force applied to the first handle via a column motor (such as column motor 420 shown in fig. 1-2 and 4A-E) and a second servomotor (such as second servomotor 212 shown in fig. 1-2 and 4A-E), respectively. The force applied to the first handle from an operator (such as operator 401 of fig. 4B-E) is at t ₃ Stop as indicated by the graph 614. In addition, at t ₃ At this point, the tube arm reaches the parked orientation, and the post reaches the first collapsed orientation, as indicated by plot 604 intersecting dashed line 606 and plot 608 intersecting dashed line 610, respectively.

After the tube arm and column parking is complete, at t ₄ The operator begins to apply a force to the second handle as indicated by plot 616. From t ₄ To t ₅ In response to a force applied to the second handle, the post collapses from the first collapsed orientation to the fully collapsed orientation, as indicated by graph 608. At t ₅ At this point, the column reaches a fully collapsed orientation, as indicated by graph 608 intersecting dashed line 612. After the column has reached the fully collapsed orientation, at t ₅ At this point, the drive wheel is actuated by the drive motor, as indicated by the graph 618. The rotational speed of the drive wheel is proportional to the force applied to the second handle via force feedback, as indicated by a comparison of graph 616 and graph 618.

From time t ₅ To t ₆ The force applied to the second handle continuously ramps up until a steady value is reached, as indicated by the graph 618. With the ramping up of the force applied to the second handle as shown in graph 616, the speed of the drive wheel as shown in graph 618 ramps up proportionally until it reaches a steady value, where the speed of the drive wheel is proportional to the force applied to the second handle via force feedback. Exceeds t ₆ The drive wheel maintains a steady speed in response to a force applied to the second handle, and the cart is transported to the second handleLocation.

Fig. 7 illustrates an exemplary timeline 700 for transitioning a mobile imaging system from an imaging configuration (such as during imaging of a patient at a first location) to moving the imaging system to a different second location. The transition includes parking a tube arm (such as tube arm 32, shown in fig. 4A-E), and collapsing a column (such as column 33, shown in fig. 1-2 and 4A-E) to a fully collapsed orientation, while concomitantly actuating a drive wheel (such as drive wheel 19, shown in fig. 1-2 and 4A-E) of a drive assembly via a drive motor (such as drive motor 52, shown in fig. 1-2 and 4A-E) to move the mobile imaging system from a first position to a second position. Horizontal (x-axis) represents time, vertical mark t ₁ –t ₆ Representing the significant time of parking, column collapse and drive wheel actuation. In this example, the rotation angle Φ is 0. The exemplary timeline 700 shows a reduction in time from imaging configuration to transport of the mobile imaging system when parking of the tube arm and collapsing of the column are accompanied by driving the mobile imaging system, as compared to the exemplary timeline 600 of fig. 6.

The timeline 700 includes a plot 702 of the radial extension of a tube arm (such as the inner section 402 of the tube arm 32 shown in fig. 4A-E), where the fully extended orientation is represented by a "+" on the y-axis and the fully retracted orientation is represented by a "-" on the y-axis. The vertical orientation of the tube arm is indicated by graph 704, where the maximum focus of the tube arm is indicated by a "+" on the y-axis, the park orientation is indicated by a "0" on the y-axis, and the minimum focus is indicated by a "-" on the y-axis. The dashed line 706 indicates the park orientation of the tube arm and is aligned with a "0" on the y-axis of the graph 704. Graph 708 indicates the vertical orientation of the column, with the maximum focus indicated by a "+" on the y-axis, the first collapsed orientation indicated by a "1" on the y-axis, and the fully collapsed orientation indicated by a "0" on the y-axis. In addition, dashed line 710 indicates a first collapsed orientation of the post corresponding to the parked orientation of the tube arm and aligned with a "1" along the y-axis of graph 708, and dashed line 712 indicates a fully collapsed orientation of the post and aligned with a "1" along the y-axis of graph 708. Graph 714 indicates the magnitude of the force applied to a first handle (such as first handle 66 shown in fig. 1-2 and 4A-E) coupled to the imaging assembly, where zero force is indicated by a "0" along the y-axis, and graph 716 indicates the magnitude of the force applied to a second handle (such as second handle 38 shown in fig. 1-2 and 4A-E) coupled to the drive assembly, where zero force is indicated by a "0" along the y-axis. Graph 720 is a graph of the speed of the drive wheel, with the stationary wheel indicated as "0" along the y-axis. Dashed line 718 indicates a first threshold speed of the drive wheel and is aligned with "+" along the y-axis of graph 720. The first threshold speed is a pre-calibrated speed at which the drive wheel may rotate when a force is applied on the second handle during parking of the tube arm.

At time t ₁ Previously, the tube arm was in an imaging configuration, where the tube arm was fully radially extended, the column was fully vertically extended to the maximum focus, and the rotation angle Φ was 0. At time t ₁ Radial retraction of the tube arm is initiated in response to a force applied to the first handle to transition the tube arm to the parked orientation. From t ₁ To t ₂ The tube arm orientation is radially retracted from a fully extended orientation to a fully retracted orientation, as shown in graph 702. In response to the force applied to the first handle, the retraction speed of the tube arm from the fully extended orientation to the fully retracted orientation is adjusted based on force feedback from a first servomotor (such as first servomotor 210, shown in fig. 1-2 and 4A-E). At time t ₂ The tube arms retract to a fully retracted orientation.

At time t ₂ The parking of the tube arm continues in response to the continued force applied to the first handle as shown in graph 714. At time t ₂ And t ₃ In between, each of the tube arms and posts are lowered to the parked orientation and the first collapsed orientation, as indicated by

graphs

704 and 708, respectively. The lowering of the column and tube arm is regulated via force feedback in response to a force applied to the first handle via a column motor (such as column motor 420 shown in fig. 1-2 and 4A-E) and a second servomotor (such as second servomotor 212 shown in fig. 1-2 and 4A-E), respectively, wherein the tube arm and column downward speed is proportional to the force applied to the first handle. At t ₃ Here, an operator (such as operator 401 of FIGS. 4B-E) stops applying force to the first handle, as shown in graph 714, and the post and tube armContinue to translate linearly downward at the same speed.

While the tube arm and column parking is in progress, such as when the tube arm and column continue to linearly translate downward in proportion to the force applied to the first handle, at t ₄ At point, the operator applies a force to the second handle, as shown in graph 716. From t ₄ To t ₅ In response to the force applied to the second handle, the drive wheel ramps up to the first threshold speed, as shown in graph 720. Since the parking of the pipe arm is in progress, at time t ₄ And t ₅ In between, regardless of the force applied to the second handle, the speed of the drive wheel is maintained at the first threshold speed, as indicated by the graph 720 intersecting the dashed line 718.

At t ₅ At this point, the tube arm reaches the parked orientation, and the post reaches the first collapsed orientation, as indicated by plot 704 intersecting dashed line 706 and plot 708 intersecting dashed line 710, respectively. After reaching the first collapsed orientation, at t ₅ To t ₆ In response to continued application of force to the second handle, the post continues to collapse to the fully collapsed position at a higher velocity than during collapse from the maximum focus to the first collapsed position. An increase in the collapse rate of the column is indicated in graph 708. In an alternative example, the collapse of the column is done at a constant speed from the maximum focus to the fully collapsed (final) orientation. In addition, upon completion of parking, at t ₅ At this point, the speed of the drive wheel increases from the first threshold speed to a second speed, as shown in graph 720, which is proportional to the force applied to the second handle.

From time t ₅ To t ₆ As indicated by the graph 716, the force applied to the second handle continuously ramps up until a steady value is reached. With the ramping up of the force applied to the second handle as shown in graph 716, the speed of the drive wheel as shown in graph 720 ramps up proportionally until it reaches a steady value, where the speed of the drive wheel is proportional to the force applied to the second handle via force feedback. Exceeds t ₆ The drive wheel maintains a steady speed in response to a force applied to the second handle, and the cart is in a transport mode. In this way, in the example shown in fig. 7, byStarting to drive the drive wheel while the tube arm is parked and the column is collapsing reduces the time to transition the mobile imaging system from the imaging configuration in the first position to a different second imaging position. For the example shown in fig. 7, the time it takes for the imaging assembly to reach the second position will be shorter relative to the time it takes for the example shown in fig. 6, in which the drive wheels may be actuated after the tube arms and posts reach the respective fully retracted positions.

In this manner, for a mobile imaging system including a radiation source coupled to a drive system via a tube arm and a column, the tube arm may be actuated to a parked orientation in response to user manipulation of a first manually-actuatable component, and then the column may be actuated to a fully collapsed orientation while moving the drive system in response to user manipulation of a second manually-actuatable component.

A technical effect of a mobile imaging system having a mechanism for collapsing the posts with a driving motion of the mobile imaging system is to reduce a time interval during a transition from an imaging configuration of the mobile imaging system to a transport configuration of the mobile imaging system. In general, the workflow of a busy clinic/hospital can be expedited by reducing the time between two scans using the imaging assembly at two different locations.

Embodiments provide a method for moving an imaging system including collapsing a column coupling an imaging assembly to a drive system while concomitantly moving the drive system when conditions are met to move the mobile imaging system. In a first embodiment of the method, the imaging assembly is coupled to the column via a rotatable and extendable tube arm, the column coupling the tube arm to the drive system. In a second embodiment of the method, which optionally includes the first embodiment, the conditions for moving the imaging system include applying a force or actuating a switch by a user on a second handle coupled to the drive system during or after parking the tube arm. In a third embodiment of the method, which optionally includes one or both of the first and second embodiments, parking of the tube arm is initiated by applying a force on a first handle coupled to the imaging assembly. In a fourth embodiment of the method, which optionally includes one or more or each of the first through third embodiments, the parking of the tube arm includes rotating the tube arm to an origin orientation, retracting the tube arm toward the column to a fully retracted orientation, and driving the tube arm vertically down the column. In a fifth embodiment of the method, which optionally includes one or more or each of the first to fourth embodiments, each of the rotation of the tube arm, the retraction of the tube arm, and the vertical drive of the tube arm is adjusted based on force feedback in response to a first signal received from a first force sensor coupled to the first handle or the tube arm. In a sixth embodiment of the method, which optionally includes one or more or each of the first to fifth embodiments, the retracting of the tube arm is further based on a first input from a first orientation sensor coupled to the column indicating a radial orientation of the tube arm, wherein the vertical driving of the tube arm is further based on a second input from a second orientation sensor coupled to the tube arm indicating a vertical orientation of the tube arm relative to the column, and wherein the rotating of the tube arm is further based on a third input from a third orientation sensor coupled to the column indicating an angular displacement of the tube arm relative to the origin orientation. In a seventh embodiment of the method, which optionally includes one or more or each of the first to sixth embodiments, collapsing the post comprises collapsing the post to a fully collapsed orientation, a rate of collapse of the post being based on another force feedback in response to a second signal received from a second force sensor coupled to the second handle. In an eighth embodiment of the method, which optionally includes one or more or each of the first through seventh embodiments, during collapsing the column, a first gas spring housed within the column is compressed to provide weight compensation while a second gas spring housed within the column expands to maintain tension in the cords. In a ninth embodiment of the method, which optionally includes one or more or each of the first through eighth embodiments, moving the drive system comprises actuating a set of drive wheels coupled to the drive system at a speed of the drive wheels, the speed of the drive wheels adjusted based on a second signal received from a second force sensor coupled to the second handle.

Embodiments provide a method for moving an imaging system including a radiation source coupled to a drive system via a tube arm and a post, the method including actuating the tube arm to a parked orientation in response to user manipulation of a first manually actuatable component, and then actuating the post to a fully collapsed orientation while moving the drive system in response to user manipulation of a second manually actuatable component. In a first embodiment of the method, actuating the tube arm to the parked orientation includes rotating the tube arm to the origin orientation via rotation of the column, retracting the tube arm horizontally to a fully retracted orientation by retracting an inner tube section within an outer tube section, and translating the tube arm vertically downward along the column. In a second embodiment of the method, which optionally includes the first embodiment, the user manipulation of the first manually actuatable component includes applying a force on the first manually actuatable component to initiate parking of the tubing arm and then releasing the first manually actuatable component. In a third embodiment of the method, optionally including one or both of the first and second embodiments, the post is collapsed by collapsing the inner post section within the inner post section until the first collapsed orientation is reached upon actuating the tube arm to the parked orientation. In a fourth embodiment of the method, which optionally includes one or more or each of the first through third embodiments, actuating the post to the fully collapsed orientation includes collapsing the post from the first collapsed orientation to the end orientation while moving the drive system via actuation of the drive wheel. In a fifth embodiment of the method, optionally including one or more or each of the first through fourth embodiments, the speed of the drive wheel is adjusted based on the force exerted on the second manually-actuatable component estimated via the force sensor, the speed being proportional to the force exerted.

Embodiments provide a system for a mobile imaging system, the system comprising a controller storing instructions executable by the controller in a non-transitory memory to: during a first condition, collapsing a column coupling a tube arm of an imaging system and the drive system at a first speed while driving the drive system forward at a second speed; and during a second condition, collapsing the column at the first speed while driving the drive system forward at a third speed, the third speed being higher than the second speed. In a first embodiment of the system, the first condition comprises receiving a second signal from the second handle when the tube arm is actuated from the scanning orientation to the parking orientation in response to the first signal received at the first handle, and the second condition comprises receiving the second signal from the second handle after the tube arm reaches the parking orientation. In a second embodiment of the system, which optionally includes the first embodiment, the parked orientation includes the tube arm in a fully retracted orientation, aligned along the drive system, and translated along the column to a lowest point of the tube arm, and the column retracted to the first orientation, and wherein upon receiving the second signal, the column collapses to an end, fully retracted orientation. In a third embodiment of the system, optionally including one or both of the first and second embodiments, the second signal includes an estimate of the force exerted on the second handle, and the fourth speed is adjusted based on the estimate of the force exerted on the second handle and the orientation of the drive system.

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly recited. Furthermore, references to "one embodiment" of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising," "including," or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property. The terms "including" and "in. Furthermore, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements or a particular positional order on their objects.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the relevant art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A method for moving an imaging system, comprising:

upon satisfaction of the conditions for moving the mobile imaging system,

upon concomitantly moving the drive system, a column coupling the imaging assembly to the drive system is collapsed.

2. The method of claim 1, wherein the imaging assembly is coupled to the column via a rotatable and extendable tube arm, the column coupling the tube arm to the drive system.

3. The method of claim 1, wherein the condition for moving the mobile imaging system comprises applying a force or actuating a switch on a second handle coupled to the drive system by a user during or after parking a tube arm.

4. The method of claim 3, wherein parking of the tube arm is initiated by applying a force on a first handle coupled to the imaging assembly.

5. The method of claim 4, wherein the parking of the tube arm comprises rotating the tube arm to an origin orientation, retracting the tube arm toward the column to a fully retracted orientation, and driving the tube arm vertically down the column.

6. The method of claim 5, wherein each of the rotation of the tube arm, the retraction of the tube arm, and the vertical drive of the tube arm is adjusted based on force feedback in response to a first signal received from a first force sensor coupled to the first handle or the tube arm.

7. The method of claim 6, wherein the retracting of the tube arm is further based on a first input from a first orientation sensor coupled to the column indicating a radial orientation of the tube arm, wherein the vertical driving of the tube arm is further based on a second input from a second orientation sensor coupled to the tube arm indicating a vertical orientation of the tube arm relative to the column, and wherein the rotating of the tube arm is further based on a third input from a third orientation sensor coupled to the column indicating an angular displacement of the column and the tube arm relative to the origin orientation.

8. The method of claim 3, wherein collapsing the post comprises collapsing the post to a fully collapsed orientation, a rate of collapse of the post being based on another force feedback responsive to a second signal received from a second force sensor coupled to the second handle.

9. The method of claim 8, wherein during collapsing the column, a first gas spring housed within the column is compressed to provide weight compensation while a second gas spring housed within the column expands to maintain tension in the cord.

10. A method for moving an imaging system comprising a radiation source coupled to a drive system via a tube arm and a column, the method comprising:

actuating the tube arm to a parked orientation in response to user manipulation of a first manually actuatable component; and

the post is then actuated to a fully collapsed orientation upon moving the drive system in response to user manipulation of a second manually actuatable component.

11. The method of claim 10, wherein actuating the tube arm to the parked orientation comprises rotating the tube arm to an origin orientation via rotation of the post, retracting the tube arm horizontally to a fully retracted orientation by retracting an inner tube section within an outer tube section, and translating the tube arm vertically downward along the post.

12. The method of claim 11, wherein user manipulation of the first manually actuatable component comprises applying a force on the first manually actuatable component to initiate parking of the tube arm and then releasing the first manually actuatable component.

13. The method of claim 10, further comprising collapsing the post by collapsing an outer post segment that encloses an inner post segment until a first collapsed orientation is reached upon actuating the tube arm to the parked orientation.

14. The method of claim 10, wherein actuating the post to the fully collapsed orientation comprises collapsing the post from a first collapsed orientation to an end orientation while moving the drive system via actuation of a drive wheel.

15. A system for a mobile imaging system, the system comprising a controller storing instructions in a non-transitory memory executable by the controller to:

collapsing a column coupling a tube arm of the mobile imaging system and a drive system at a first speed while driving the drive system forward at a second speed during a first condition; and

during a second condition, collapsing the column at a first speed while driving the drive system forward at a third speed, the third speed being higher than the second speed.